Method and system for blocker attenuation using multiple receive antennas

ABSTRACT

Methods and systems for blocker attenuation using multiple receive antennas are disclosed. In this regard, a plurality of signals may be received via a corresponding plurality of antennas and a corresponding plurality of interference-suppressed signals may be generated. The interference-suppressed signals may be generated by adjusting a gain and phase of the plurality of received signals to generate a corresponding plurality of adjusted signals, and combining the corresponding plurality of adjusted signals, respectively, with the plurality of received. The gain of the received signals may be adjusted based on a wide bandwidth signal strength measurement and a narrow bandwidth signal strength measurement. A center frequency of one or more of the plurality of antennas may be adjusted based on received signals strength measurements. A gain and/or phase adjustment of each one of said received signals may be independent of gain and/or phase adjustments of other ones of the receive signals.

CROSS-REFERENCE TO RELATED APPLICATIONS/INCORPORATION BY REFERENCE

This application is a continuation of U.S. patent application Ser. No.12/613,489 filed on Nov. 5, 2009 which in turn is a continuation of U.S.patent application Ser. No. 11/536,688 filed on Sep. 29, 2006.

This application makes reference to:

-   U.S. application Ser. No. 11/536,678 filed on Sep. 29, 2006-   U.S. application Ser. No. 11/536,682 filed on Sep. 29, 2006;-   U.S. application Ser. No. 11/536,650 filed on Sep. 29, 2006;-   U.S. application Ser. No. 11/536,644 filed on Sep. 29, 2006;-   U.S. application Ser. No. 11/536,676 filed on Sep. 29, 2006;-   U.S. application Ser. No. 11/536,659 filed on Sep. 29, 2006;-   U.S. application Ser. No. 11/536,673 filed on Sep. 29, 2006;-   U.S. application Ser. No. 11/536,679 filed on Sep. 29, 2006;-   U.S. application Ser. No. 11/536,670 filed on Sep. 29, 2006;-   U.S. application Ser. No. 11/536,672 filed on Sep. 29, 2006;-   U.S. application Ser. No. 11/536,648 filed on Sep. 29, 2006;-   U.S. application Ser. No. 11/536,669 filed on Sep. 29, 2006;-   U.S. application Ser. No. 11/536,666 filed on Sep. 29, 2006;-   U.S. application Ser. No. 11/536,675 filed on Sep. 29, 2006;-   U.S. application Ser. No. 11/536,685 filed on Sep. 29, 2006;-   U.S. application Ser. No. 11/536,645 filed on Sep. 29, 2006;-   U.S. application Ser. No. 11/536,655 filed on Sep. 29, 2006;-   U.S. application Ser. No. 11/536,660 filed on Sep. 29, 2006;-   U.S. application Ser. No. 11/536,657 filed on Sep. 29, 2006;-   U.S. application Ser. No. 11/536,662 filed on Sep. 29, 2006;-   U.S. application Ser. No. 11/536,667 filed on Sep. 29, 2006;-   U.S. application Ser. No. 11/536,651 filed on Sep. 29, 2006;-   U.S. application Ser. No. 11/536,656 filed on Sep. 29, 2006; and-   U.S. application Ser. No. 11/536,663 filed on Sep. 29, 2006.

Each of the above stated applications is hereby incorporated herein byreference in its entirety.

FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[Not Applicable]

MICROFICHE/COPYRIGHT REFERENCE

[Not Applicable]

FIELD OF THE INVENTION

Certain embodiments of the invention relate to wireless communication.More specifically, certain embodiments of the invention relate to amethod and system for blocker attenuation using multiple receiveantennas.

BACKGROUND OF THE INVENTION

Wireless devices have used antennas to receive RF signals. However,signals received by an antenna may be affected by a transmission pathtaken by the signals, as well as by characteristics of the receiveantenna. For example, the transmission path may comprise obstacles, suchas, for example, buildings and/or trees that reflect and/or attenuatetransmitted signals. Additionally, the receive antenna may also receiveinterfering signals in the desired channel that may reduce thesignal-to-noise ratio (SNR) of at least a portion of the receivedbandwidth, thereby increasing the difficulty of demodulating the desiredsignal. If the interfering signals are strong enough, the receivingwireless device may not be able to de-modulate the desired signal fromthe desired channel. These interfering signals may be referred to asblocking signals or blockers.

Multi-antenna designs have increased the ability to transmit and receiveRF signals more robustly, that is, with more throughput and fewer errorswithout using more power. While the use of multiple transmit and/orreceive antennas is designed to introduce a diversity gain and arraygain, blockers may disrupt reception and demodulation of RF signals.

Further limitations and disadvantages of conventional and traditionalapproaches will become apparent to one of skill in the art, throughcomparison of such systems with some aspects of the present invention asset forth in the remainder of the present application with reference tothe drawings.

BRIEF SUMMARY OF THE INVENTION

A system and/or method for blocker attenuation using multiple receiveantennas, substantially as shown in and/or described in connection withat least one of the figures, as set forth more completely in the claims.

Various advantages, aspects and novel features of the present invention,as well as details of an illustrated embodiment thereof, will be morefully understood from the following description and drawings.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a block diagram of a wireless terminal, in accordance with anembodiment of the invention.

FIG. 2A is a block diagram illustrating exemplary circuitry that may beused for blocker attenuation, in accordance with an embodiment of theinvention.

FIG. 2B is a block diagram illustrating exemplary circuitry that may beused for blocker attenuation, in accordance with an embodiment of theinvention.

FIG. 3 is a chart illustrating exemplary signal strengths for a channelas a center frequency is changed due to antenna hopping, in accordancewith an embodiment of the invention.

FIG. 4 is an exemplary diagram illustrating a blocker in desiredsignals, in accordance with an embodiment of the invention.

FIG. 5 is a flow diagram of exemplary steps for blocker attenuation, inaccordance with an embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Certain embodiments of the invention may be found in a method and systemfor blocker attenuation using multiple receive antennas. Aspects of themethod may comprise receiving signals by a wideband diversity radiofrequency (RF) receiver comprising a plurality of receiving antennas.The receiver may process received signals that may comprise a blockingsignal, where the received signals may be received via one of themultiple antennas. The receiver may also process received signals,received via another of the multiple antennas, which may compriseanother blocking signal. The blocker received by a first antenna may besuppressed, at least in part, by combining processed signals received byone antenna with processed signals received by another antenna. Thecombining may comprise, for example, adding the two processed signals ateither the RF or corresponding IF. The processing of the signals whoseblocker is to be suppressed may comprise gain adjustment. The processingof the signals that is to be used to suppress the blocker of the otherantenna may be gain and/or phase adjustment.

FIG. 1 is a block diagram of an exemplary wireless terminal, inaccordance with an embodiment of the invention. Referring to FIG. 1,there is shown a wireless terminal 100, which may comprise, for example,a plurality of antennas 105 a . . . 105 b, a RF front end 110, abaseband processor 114, a processor 116, and a system memory 118. The RFfront end 110 may comprise suitable logic, circuitry, and/or code thatmay be adapted to process received RF signals and/or RF signals to betransmitted. The RF front end 110 may be coupled to the antenna 105 forsignal reception and/or transmission. The RF front end 110 may comprisean received signal strength indicator (RSSI) circuit 111, an antennatuning circuit block 112, and a filter circuit 113.

The RSSI circuit 111 may comprise suitable logic, circuitry, and/or codethat may be adapted to enable generation of received signal strength.The RSSI circuit 111 may generate received signal strength indicationsfor a wide bandwidth spectrum and for a narrow bandwidth spectrum. Thewide bandwidth spectrum may be, for example, the bandwidth for a WCDMAtransmission while the narrow bandwidth spectrum may be, for example, todetect signal strength of a blocker. For example, if there is noblocker, the narrow bandwidth signal strength indication may besubstantially similar to the broad bandwidth signal strength indication.However, in the presence of a blocker within the wide bandwidthspectrum, the narrow bandwidth signal strength indication may besubstantially larger than the signal strength indication for the widebandwidth. Determination of a difference between the narrow bandwidthsignal strength indication may differ from the wide bandwidth signalstrength indication may be design and/or implementation dependent. Thepresence of a blocker may be determined by, for example, the basebandprocessor 114 and/or the processor 116 by processing the signalstrengths of the wide bandwidth spectrum and the narrow bandwidthspectrum.

The RSSI circuit 111 may be able to generate a signal strengthindication for the narrow bandwidth spectrum by varying the frequencyrange of the narrow bandwidth spectrum. Accordingly, the RSSI circuit111 may detect a blocker at various frequency ranges within the widebandwidth spectrum. An embodiment of the invention may vary thefrequency range for the narrow bandwidth spectrum by, for example,bandpass filtering received signals in the wide bandwidth spectrum. Thebandpass filter bandwidth may be indicated and/or controlled by, forexample, the processor 116 and/or the baseband processor 114.Accordingly, the RSSI circuit 111 may generate a wide bandwidth signalstrength indication and a narrow bandwidth signal strength indicationfor signals received by each of the antennas 105 a . . . 105 b.

The antenna tuning circuit block 112 may comprise suitable logic,circuitry, and/or code that may be adapted to adjust a center frequencyfor each of the antennas 105 a . . . 105 b that may be in use. Anexemplary description of dynamic tuning of an antenna is disclosed inU.S. patent application Ser. No. 11/536,678 filed on Sep. 29, 2006 andis incorporated by reference in its entirety. The filter circuit 113 maycomprise suitable logic, circuitry, and/or code that may be adapted tobandpass filter RF and/or IF frequencies. The filter circuit 113 may beadjusted to change, for example, bandpass frequencies. The adjustment ofbandpass characteristics may be indicated and/or controlled by, forexample, the processor 116 and/or the bandpass processor 114.

With respect to received signals, the RF front end 110 may demodulatethe received signals before further processing. Moreover, the RF frontend 110 may comprise other exemplary RF processing functions, such as,filtering the received signal, amplifying the received signals, and/ordownconverting the received signals to intermediate frequency, very lowintermediate frequency (VLIF) signal, and/or baseband signal. The RFfront end 110 may comprise a IF processor which may digitize an IFsignal, and digitally process the digitized IF signal to filter and/ordownconvert the digitized IF signal to a digital baseband signal. The IFprocessor may then convert the digitized baseband signal to an analogbaseband signal.

The RF front end 110 may also receive digital or analog baseband signalsfrom, for example, the baseband processor 114. For example, the basebandprocessor 114 may generate one or more signals that may be communicatedto the RF front end 110, which may be utilized to control one or morefunctions executed by the RF front 110. Accordingly, in one embodimentof the invention, one or more signals generated by the basebandprocessor 114 and/or processor 116 may be utilized to program variouscomponents such as, for example, filters, phase lock loops (PLLs) orsynthesizers, in the RF front end 110. The RF front end 110 mayappropriately filter, amplify, and/or modulate an analog signal fortransmission via the antenna 105. The RF front end 110 may also converta digital signal to an analog signal as part of processing fortransmission.

The baseband processor 114 may comprise suitable logic, circuitry,and/or code that may be adapted to process analog or digital basebandsignals generated by the RF front end 110. The baseband processor 114may also communicate baseband signals to the RF front end 110 forprocessing before transmission. The baseband processor 114 may alsocomprise a buffer 114 a that may be used to store received data and/ordata to be transmitted. The processor 116 may comprise suitable logic,circuitry, and/or code that may be adapted to control the operations ofthe RF front end 110, the antenna tuning circuit 112, and/or thebaseband processor 114. For example, the processor 116 may be utilizedto update and/or modify programmable parameters and/or values in aplurality of components, devices, and/or processing elements in the RFfront end 110, the antenna tuning circuit 112, and/or the basebandprocessor 114. Exemplary programmable parameters may comprise gain of anamplifier, phase of a phase adjusting block, bandwidth of a filter,and/or PLL parameters. Control and/or data information may betransferred from another controller and/or processor in the wirelessterminal 100 to the processor 116. Similarly, the processor 116 maytransfer control and/or data information to another controller and/orprocessor in the wireless terminal 100.

The processor 116 may utilize the received control and/or datainformation to determine the mode of operation of the RF front end 110.For example, the processor 116 may select a specific frequency for alocal oscillator, or a specific gain for a variable gain amplifier.Moreover, the specific frequency selected and/or parameters needed tocalculate the specific frequency, and/or the specific gain value and/orthe parameters needed to calculate the specific gain, may be stored inthe system memory 118 via the controller/processor 116. This informationstored in system memory 118 may be transferred to the RF front end 110from the system memory 118 via the controller/processor 116.

The system memory 118 may comprise suitable logic, circuitry, and/orcode that may be adapted to store a plurality of control and/or datainformation, including parameters needed to calculate frequencies and/orgain, and/or the frequency value and/or gain value. The system memory118 may also store, for example, various parameters for enabling and/ordisabling RF processing circuitry as well as for controlling antennahopping. The antenna hopping parameters may comprise, for example,various antenna tuning circuit parameters to determine centerfrequencies and bandwidths of the antenna 105, as well as impedancematch the antenna 105 to the RF front end 110. An exemplary descriptionof antenna hopping is disclosed further in U.S. patent application Ser.No. 11/536,682 filed on Sep. 29, 2006 and is incorporated by referencein its entirety.

The wireless terminal 100 may support wireless protocols that requiremultiple antennas for reception and transmission, such as, for example,WCDMA. Accordingly, the RF front end 110 may comprise separate RFprocessing circuitry for processing RF signals received via, forexample, the antennas 105 a . . . 105 b, and for processing signals tobe transmitted via the antennas 105 a . . . 105 b. The RF processingcircuitry may, for example, amplify, phase adjust, filter, modulate,and/or demodulate analog signals. The RF processing circuitry may also,for example, upconvert and/or downconvert between RF frequencies, IFfrequencies, and baseband frequencies.

In operation, RF signals may be received and transmitted by the wirelessterminal 100 via the antenna 105 a . . . 105 b. If the wireless terminal100 is receiving WCDMA signals, the WCDMA signals may be received by theplurality of antennas 105 a . . . 105 b. Similarly, if the wirelessterminal 100 is transmitting WCDMA signals, the WCDMA signals may betransmitted by the plurality of antennas 105 a . . . 105 b. The RFsignals to, or from, the antennas 105 a . . . 105 b may be processed byseparate RF processing circuitry.

The antenna tuning circuit 112 may present an impedance to the antenna105, and accordingly, the antenna 105 in conjunction with the antennatuning circuit 112 may have a center frequency and a bandwidth about thecenter frequency. The antenna tuning circuit 112 may also impedancematch the antenna 105 to the RF front end 110. Accordingly, the antenna105 may present optimal reception for those signals within thebandwidth.

However, various environmental conditions may cause the center frequencyto drift from the desired center frequency. For example, if the wirelessterminal 100 is a mobile terminal, the inductive or capacitivecharacteristics of a user's hand holding the mobile terminal may changethe center frequency. The wireless terminal 100 may detect the centerfrequency drift and may dynamically configure the antenna tuning circuitblock 112 in order to bring the center frequency closer to a desiredcenter frequency. The RF front end 110, which may receive weak signalsat the desired frequencies, may be enabled to detect the centerfrequency drift, for example. The center frequency drift may also bedetected, for example, by processing the received signals. For example,the baseband processor 114 may detect an increase in bit error rate ofthe received packets, which may be indicative of center frequency drift.

The signal strength indication and/or bit error rate may be communicatedto the processor 116, and the processor 116 may determine that theantenna tuning circuit block 112 may need to be reconfigured.Accordingly, the processor 116 may communicate appropriate controland/or data to the antenna tuning circuit block 112 to reconfigureand/or retune the antenna tuning circuit block 112. By processinginformation regarding the received signals, the processor 116 maydynamically adjust the center frequency in order to reduce the effectsof center frequency drift. The processor 116 may also reconfigure theantenna tuning circuit block 112 to adjust the bandwidth of the antenna105 and/or impedance matching of the antenna 105 and the RF front end110

While FIG. 1 may have been described as communicating to at least oneother processor or controller, the invention need not be so limited.Accordingly, there may be instances when the processor 116 may not haveto communicate with other processors in controlling RF communications.For example, a design of the wireless terminal may not utilize otherprocessors than the processor 116 or the processor 116 may have accessto all information needed to control RF communications. Additionally,the RSSI circuit 111 may have been shown as part of the RF front end110. The invention need not be so limited. For example, the RSSI circuit111 may be before the RF front end 110, part of the RF front end 110,and/or after the RF front end 110.

FIG. 2A is a block diagram illustrating exemplary circuitry that may beused for blocker attenuation, in accordance with an embodiment of theinvention. Referring to FIG. 2A, there is shown a plurality of antennas205 a, 205 b, 205 c, and 205 d, low noise amplifiers (LNAs) 210, 214,220, 224, 230, 234, 240, and 244, signal combiners 212, 222, 232, and242, and phase adjuster blocks 216, 226, 236, and 246. The LNAs 210,214, 220, 224, 230, 234, 240, and 244 may comprise suitable logic,circuitry, and/or code that may be adapted to amplify RF signalsreceived by, for example, the antennas 205 a, 205 b, 205 c, and 205 d.In an embodiment of the invention, the LNAs 210, 220, 230, and 240 mayhave a fixed gain while the LNAs 214, 224, 234, and 244 may havevariable gains. However, the invention need not be so limited. Forexample, other embodiments of the invention may be able to adjust a gainof each of the LNAs 210, 214, 220, 224, 230, 234, 240, and 244.

An indication of the gain of each of the variable gain LNAs 214, 224,234, and 244 may be provided by, for example, the baseband processor 114and/or the processor 116. For example, the baseband processor 114 maycommunicate appropriate signals to the LNA 214, which may be utilized toincrease, decrease or maintain an output gain of the LNA 214. The signalcombiners 212, 222, 232, and 242 may comprise suitable circuitry thatmay enable, for example, combining two analog signals. The phaseadjuster blocks 216, 226, 236, and 246 may comprise suitable logic,circuit, and/or code that may be adapted to process an input analogsignal to generate an output analog signal with a desired phase. Theamount of phase adjustment that may be required may be indicated by, forexample, the baseband processor 114 and/or the processor 116. Forexample, the baseband processor 114 may generate various signals, whichmay be communicated to the phase adjuster block 216 so as to adjust thephase of the output analog signal with respect to the input analogsignal.

In operation, the antennas 205 a, 205 b, 205 c, and 205 d may receive RFsignals, such as, for example, WCDMA signals from a WCDMA cell site (notshown). The received RF signals may comprise desired signals and anundesired blocker. The desired signals and the undesired blocker may bereceived, for example, at varying strengths and phases by each of theantennas 205 a, 205 b, 205 c, and 205 d. Accordingly, it may bedesirable to attenuate the blockers received by antennas 205 a, 205 b,205 c, and 205 d. The presence of a blocker may be indicated by, forexample, an increase in bit error rate (BER, and/or a decrease insignal-to-noise ratio (SNR). Another exemplary manner in which thepresence of a blocker may be identified is to determine when a receivedsignal strength indication (RSSI) for the desired wide bandwidthspectrum is less than a RSSI for a narrow bandwidth spectrum. This isdiscussed with respect to FIG. 4. The wide bandwidth signal strengthindication and the narrow bandwidth signal strength indication may begenerated by, for example, the RSSI circuit 111. Accordingly, the RSSIcircuit 111 may generate separate wideband and narrowband signalstrength indications for signals received from each of the antennas 205a, 205 b, 205 c, and 205 d.

The RF signals received from an antenna, for example, the antenna 205 a,may be appropriately adjusted in gain and/or phase by the LNA 214 andthe phase adjuster block 216, respectively, and communicated to thesignal combiner 222. The RF signals received from another antenna, forexample, the antenna 205 b, may be amplified by, for example, the LNA220, and the amplified RF signal may be communicated to the signalcombiner 222. The signal combiner 222 may combine the signals receivedby the antennas 205 a and 205 b to generate an output signal. The outputsignal may be further processed by the RF front end 110. The outputsignal from the signal combiner 222 may also be processed by the RSSIcircuit 111 to generate a wide bandwidth signal strength indication anda narrow bandwidth signal strength indication.

A processor, for example, the processor 116, may process the signalstrength indications to determine further gain and/or phase adjustmentsfor the LNA 214 and the phase adjuster block 216, respectively. Byappropriately adjusting the gain and phase of the received signal fromthe antenna 205 a, the blocker received by the antenna 205 a may be usedto attenuate the blocker received by the antenna 205 b to a satisfactorylevel. The amount of attenuation desired may be design and/orimplementation dependent.

Similarly, the blocker received by the antenna 205 c may be attenuatedby combining it with appropriately processed signals received from theantennas 205 b. The received signal from the antenna 205 b may beprocessed by the LNA 224 and the phase adjuster block 226, and combinedwith the amplified signal from the LNA 230 by the signal combiner 232.The blocker received by the antenna 205 d may be attenuated in a similarmanner by combining it with appropriately processed signals receivedfrom the antennas 205 c. The received signal from the antenna 205 c maybe processed by the LNA 234 and the phase adjuster block 236, andcombined with the amplified signal from the LNA 240 by the signalcombiner 242. The blocker received by the antenna 205 a may also beattenuated by combining it with appropriately processed signals receivedfrom the antennas 205 d. The received signal from the antenna 205 d maybe processed by the LNA 244 and the phase adjuster block 246, andcombined with the amplified signal from the LNA 210 by the signalcombiner 212. Accordingly, each antenna in a multiple antenna wirelessterminal may reduce a blocker by using appropriately processed signalfrom another antenna, where signals for each antenna may beindependently processed.

While an embodiment of the invention may have been described withrespect to FIG. 2A, the invention need not be so limited. Otherembodiments of the invention may be used for a number of antennas otherthan four antennas. Additionally, other embodiments of the invention maygroup functionalities described with respect to FIG. 2A in other ways.For example, in another embodiment of the invention, a phase of the RFsignals may be adjusted before amplifying the signal. Another exemplaryembodiment of the invention may combine the phase adjustment and gaincircuitry into one circuit block.

FIG. 2B is a block diagram illustrating exemplary circuitry that may beused for blocker attenuation, in accordance with an embodiment of theinvention. Referring to FIG. 2B, there is shown the antennas 205 a and205 b, the LNAs 210, 214, 220, and 224, the phase adjust blocks 216 and226, mixers 250, 256, 264, local oscillators 254, 258, and 264, andsignal combiners 252 and 262. Blocker attenuation may be performed in amethod similar to the method described with respect to FIG. 2A. However,rather than remove a blocker from the received RF signal, the blockermay be removed after down converting the RF signal to, for example, anIF signal. The signal strength indication for the wide bandwidthspectrum and the narrow bandwidth spectrum may accordingly be determinedby, for example, the RSSI circuit 111 using the IF signal.

In operation, the antenna 205 b may receive wideband RF signals in thedesired frequency range that may include a blocker. The received RFsignals may be amplified by the LNA 220 and communicated to the mixer260. The mixer 260 may mix the amplified RF signals with a signal fromthe local oscillator 264. The IF signals output by the mixer 260 may becommunicated to the signal combiner 262. Signals received by the antenna205 a, which may have been down converted by the mixer 256, may becommunicated to the signal combiner 262. The signal combiner 262 maycombine the signals received by the antennas 205 a and 205 b to generatean output signal. The output signal may be further processed by the RFfront end 110. The output signal from the signal combiner 222 may alsobe processed by the RSSI circuit 111 to generate a wide bandwidth signalstrength indication and a narrow bandwidth signal strength indication.

A processor, for example, the processor 116, may process the signalstrength indications to determine further gain and/or phase adjustmentsfor the LNA 214 and the phase adjuster block 216, respectively. Byappropriately adjusting the gain and phase of the received signal fromthe antenna 205 a, the blocker received by the antenna 205 a may be usedto attenuate the blocker received by the antenna 205 b to a satisfactorylevel. The amount of attenuation desired may be design and/orimplementation dependent.

In a similar manner, the blocker received by the antenna 205 a may beindependently attenuated by appropriate gain and phase adjustment of theoutput signal of the LNA 220. Accordingly, the signal combiner 252 maycombine the signals received by the antennas 205 a and 205 b to generatean output signal. The output signal may be used to generate a widebandwidth signal strength indication and a narrow bandwidth signalstrength indication. The processor 116, for example, may process thesignal strength indications to determine further phase and/or gainadjustments for appropriate attenuation of the blocker received by theantenna 205 a.

While an embodiment of the invention may have been described withrespect to FIG. 2B, the invention need not be so limited. Otherembodiments of the invention may use more than two antennas.Additionally, other embodiments of the invention may groupfunctionalities described with respect to FIG. 2B in other ways. Forexample, another embodiment may phase adjust RF signals beforeamplifying the signal, or after down-converting by, for example, themixer 256. Another embodiment of the invention may combine the phaseadjustment and gain circuitry into one circuit block. Another embodimentof the invention may incorporate the phase adjustment functionality intothe local oscillator block 258, for example. Accordingly, the phase ofthe signal from the local oscillator block 258, for example, may beadjusted before being communicated to the mixer 256.

Although FIG. 2B does not illustrate I and Q components of the IFsignals, the invention need not be limited in this manner. Accordingly,the I and Q components of the IF signal may also be utilized. Forexample, blocker attenuation may be generalized to I and Q componentsfor signals received from each antenna. Accordingly, the I component ofone antenna may be used to reduce a blocker for the I component ofanother antenna, and similarly for the Q components.

FIG. 3 is a chart illustrating exemplary signal strengths for a channelas a center frequency is changed due to antenna hopping, in accordancewith an embodiment of the invention. Referring to FIG. 3, there is showna chart where the horizontal axis indicates frequency and the verticalaxis indicates signal strength. If there is a frequency offset betweenthe desired channel, and the center frequency of, for example, theantenna 105 a, the wireless terminal 100 may not be able to determinethe frequency offset. Accordingly, in an embodiment of the invention,after switching to an antenna, for example, the antenna 105 a, thewireless terminal 100 may antenna hop by tuning the antenna 105 a tochange the center frequency of the antenna 105 a to various frequencies.

For example, the desired channel frequency, and the desired centerfrequency, may be at the frequency f_(DC) while the actual centerfrequency may have drifted to, for example, actual center frequency 305of f_(CFA). While the wireless terminal 100 may have no indication thatthe actual center frequency 305 is a different frequency than thedesired center frequency, an antenna hopping algorithm may still beapplied. Accordingly, signals for the desired channel may be receivedfor various center frequencies. For example, the first antenna hop mayconfigure the antenna tuning circuit 112 to a center frequency 313 atthe frequency f_(CA1). Since the center frequency 313 may be close tothe desired channel frequency f_(DC), the signal strength 312 for thedesired channel for the center frequency f_(CA1) may be a normalizedvalue of 0.9.

The next antenna hop may configure the antenna tuning circuit 112 to acenter frequency 315 at the frequency f_(CA2). Since the centerfrequency 315 may be farther away from the desired channel frequencyf_(DC) than the center frequency 313 may be from the desired channelfrequency f_(DC), the signal strength 314 for the desired channel forthe center frequency f_(CA2) may be at a smaller normalized value of0.4. Antenna hops may be configured so that adjacent antenna bandwidthsmay overlap. For example, the antenna bandwidth associated with thecenter frequency 313 may overlap a portion of the antenna bandwidthassociated with the center frequency 315.

In this manner, the wireless terminal 100 may be able to receive signalsfor the desired channel from different center frequencies associatedwith the antenna 105 a at various times. Accordingly, the wirelessterminal 100 may be able to compensate for center frequency driftwithout knowing the specific amount of drift. The wireless terminal 100may be able to use antenna hopping to increase signal strength forreceived desired signals, which may reduce the amount of attenuation ofa blocker received with the desired signals.

FIG. 4 is an exemplary diagram illustrating a blocker in desiredsignals, in accordance with an embodiment of the invention. Referring toFIG. 4, there is shown a chart where the horizontal axis indicatesfrequency and the vertical axis indicates signal strength. For example,a desired wide bandwidth spectrum 400 for WCDMA may be from frequency F₁to frequency F₂. The wide bandwidth spectrum 400 may generally have, forexample, a normalized signal level of 0.5. Unwanted blocker 405 may alsohave been received long with desired signals within the wide bandwidthspectrum 400. The blocker 405 may exist within a narrow bandwidthspectrum 402 of frequency F_(a) to frequency F_(b). The signal strengthwithin the frequency range F_(a) to F_(b) may have a normalized signallevel of 1. Accordingly, the blocker 405 may saturate the RF front end110 such that desired signals within a portion of the frequency rangeF_(a) to F_(b) may not be recovered.

However, by using the method described with respect to FIG. 2A and/orFIG. 2B, for example, the blocker 405 may be attenuated. Accordingly,the signal strength level for the narrow bandwidth spectrum 402 fromfrequency F_(a) to frequency F_(b) may decrease as the blocker 405 getsattenuated. As the blocker 405 gets attenuated, the signal strengthlevel for the wide bandwidth spectrum 400 from frequency F₁ to frequencyF₂ may also decrease. However, the signal strength level for the widebandwidth spectrum 400 may not decrease as much as the signal strengthlevel for the narrow bandwidth spectrum 402. Accordingly, as the narrowbandwidth signal strength approaches the wide bandwidth signal strength,a processor, for example, the processor 116 may determine that theblocker 405 may have been attenuated sufficiently.

FIG. 5 is a flow diagram of exemplary steps for blocker attenuation, inaccordance with an embodiment of the invention. Referring to FIG. 5,there is shown steps 500 to 510 for reducing a blocker received by theantenna 205 b with signals received by the antenna 205 a. In step 500,the wireless terminal 100 may receive signals via the antennas 205 a and205 b. The RSSI circuit 111 may determine a wide bandwidth signalstrength level for signals received via the antenna 205 b. In step 502,the RSSI circuit 111 may determine a narrow bandwidth signal strengthfor signals received via the antenna 205 b. The RSSI circuit 111 maydetermine a plurality of narrow bandwidth signal strengths since, forexample, the wide bandwidth spectrum may comprise multiple narrowbandwidths. Accordingly, the processor 116 may, for example, configurethe filter circuit 113 to bandpass desired narrow bandwidth spectrums offrequencies from frequency F₁ to frequency F₂. The processor 116 may,for example, compare the narrow bandwidth signal levels to select thelargest narrow bandwidth signal level.

In step 504, the processor 116 may compare, for example, the largestnarrow bandwidth signal level with the wide bandwidth signal level. Ifthe difference in signal levels is greater than a specific value, thenext step may be step 506. Otherwise, the next step may be step 500. Thespecific value may be may be pre-determined, or dynamically determined.Dynamic determination may be based on, for example, signal strength ofthe wide bandwidth spectrum, bit error rate, and/or throughput. In step506, the processor 116, for example, may adjust a gain of the LNA 214and/or the phase adjustment for the phase adjust block 216. Accordingly,the RF signal received by the antenna 205 a may be adjusted in signalstrength and/or phase and combined with the amplified RF signal receivedby the antenna 205 b. In step 508, the RSSI circuit 111 may determinethe wide bandwidth signal strength level. The RSSI circuit 111 may alsodetermine the signal strength level for the narrow bandwidth spectrumdetermined in step 502 to have the largest signal strength level. Instep 510, the signal strength levels may be compared. If the differencebetween the signal strength levels is greater than a specific value, thenext step may be step 506. Otherwise, the next step may be step 500.

Although FIG. 5 discloses an exemplary embodiment of the invention, theinvention need not be limited so. For example, the narrow bandwidthsignal strength level may be determined for all narrow bandwidthspectrums in step 508, rather than just for the narrow bandwidthspectrum determined in step 502.

In accordance with an embodiment of the invention, aspects of anexemplary system may comprise the wireless terminal 100 processingsignals received by, for example, the antenna 105 a and 105 b. Thesignals received by the antenna 105 a and 105 b may comprise blockers.The wireless terminal 100 may enable suppressing, at least in part, theblocker received via the antenna 105 a by combining the processedsignals received by the antenna 105 b with the processed signalsreceived via the antenna 105 a. Processing of the signals received bythe antenna 105 a may comprise gain adjustment, while processing of thesignals received by the antenna 105 b may comprise gain adjustmentand/or phase adjustment. The processed signals may be combined at RFfrequencies or at IF frequencies. Combining of the signals may comprise,for example, adding of the signals. The wireless terminal 100 may alsoreconfigure the antennas 105 a and 105 b to operate via at least one ofa plurality of different center frequencies within a specified rangewhen receiving signals.

Another embodiment of the invention may provide a machine-readablestorage, having stored thereon, a computer program having at least onecode section executable by a machine, thereby causing the machine toperform the steps as described above for blocker attenuation usingmultiple receive antennas.

Accordingly, the present invention may be realized in hardware,software, or a combination of hardware and software. The presentinvention may be realized in a centralized fashion in at least onecomputer system, or in a distributed fashion where different elementsare spread across several interconnected computer systems. Any kind ofcomputer system or other apparatus adapted for carrying out the methodsdescribed herein is suited. A typical combination of hardware andsoftware may be a general-purpose computer system with a computerprogram that, when being loaded and executed, controls the computersystem such that it carries out the methods described herein.

The present invention may also be embedded in a computer programproduct, which comprises all the features enabling the implementation ofthe methods described herein, and which when loaded in a computer systemis able to carry out these methods. Computer program in the presentcontext means any expression, in any language, code or notation, of aset of instructions intended to cause a system having an informationprocessing capability to perform a particular function either directlyor after either or both of the following: a) conversion to anotherlanguage, code or notation; b) reproduction in a different materialform.

While the present invention has been described with reference to certainembodiments, it will be understood by those skilled in the art thatvarious changes may be made and equivalents may be substituted withoutdeparting from the scope of the present invention. In addition, manymodifications may be made to adapt a particular situation or material tothe teachings of the present invention without departing from its scope.Therefore, it is intended that the present invention not be limited tothe particular embodiment disclosed, but that the present invention willcomprise all embodiments falling within the scope of the appendedclaims.

1-20. (canceled)
 21. A system for wireless communication, the systemcomprising: one or more processors operable to: receive a plurality ofsignals; adjust a gain and a phase of at least a portion of theplurality of received signals to generate a plurality of adjustedsignals; and combine the at least a portion of the plurality of receivedsignals and the plurality of adjusted signals to generate a suppressedsignal, wherein a power of a desired transmission in the at least aportion of the plurality of received signals as compared to a power ofan interfering transmission is greater in the suppressed signal than inthe at least a portion of the plurality of received signals.
 22. Thesystem of claim 21, wherein the one or more processors receive theplurality of signals via a plurality of corresponding antennas.
 23. Thesystem of claim 21, wherein the plurality of signals are complexsignals.
 24. The system of claim 21, wherein the plurality of signalscomprises RF signals.
 25. The system of claim 21, wherein the pluralityof signals comprises IF signals.
 26. The system of claim 21, wherein theplurality of signals comprises digital baseband signals.
 27. A methodfor wireless communication, the method comprising: receiving a pluralityof signals; adjusting a gain and a phase of at least a portion of theplurality of received signals to generate a plurality of adjustedsignals; and combining the at least a portion of the plurality ofreceived signals and the plurality of adjusted signals to generate asuppressed signal, wherein a power of a desired transmission in the atleast a portion of the plurality of received signals as compared to apower of an interfering transmission is greater in the suppressed signalthan in the at least a portion of the plurality of received signals. 28.The method of claim 27, wherein the one or more processors receive theplurality of signals via a plurality of corresponding antennas.
 29. Thesystem of claim 21, wherein the plurality of signals are complexsignals.
 30. The system of claim 21, wherein the plurality of signalscomprises RF signals.
 31. The system of claim 21, wherein the pluralityof signals comprises IF signals.
 32. The system of claim 21, wherein theplurality of signals comprises digital baseband signals.